The Italian optical link for time and frequency

The Italian Institute of Metrology (INRIM) developed an optical fibre backbone for the dissemination of accurate time and frequency standards to several research institutions of the Country. A network of research facilities, involved in areas ranging from atom and molecular spectroscopy to Very Long Baseline Interferometry (VLBI) for geodesy and radioastronomy, has been established. The time transfer over fibre has also been implemented for industrial users. We will describe the status of this 1800 km long facility, the most recent implementations and the research activities where fiber-based frequency dissemination is being exploited.